Morrissey didn't reveal whether he may appear in the 50th anniversary episode, but said that he is still "very proud" of his role on the show in 'The Next Doctor'.

When asked if he would appear, he told BANG Showbiz: "I can't say anything about Doctor Who, but yeah, I would [go back]. I'm a big fan, it was a big part of my life.

''I went to Comic-Con this year and my character hadn't been announced for The Walking Dead, so it was great. I thought I could walk around the floor and be fine, but none of the other cast could. But I'd forgotten about Doctor Who.

''I walked out and all these Doctor Who fans are going crazy and I was like, 'Oh yeah, I forgot I was in that.'

''I'm very proud of my association with Doctor Who, it's great. But I can't let you know anything about the future of that.''